#include <stdio.h>
#include <errno.h>
#include <string.h>
#include <unistd.h>
#include <sys/types.h>
#include <sys/socket.h>
#include <arpa/inet.h>
#include <stdlib.h>
#include <getopt.h>
#include <pthread.h>
#include <ctype.h>

typedef void *(THREAD_BODY) (void *thread_arg);
void *thread_worker(void *ctx);
int thread_start(pthread_t * thread_id, THREAD_BODY * thread_workbody, void *thread_arg);

void print_usage(char *progname)
{
       	printf("%s usage: \n", progname);
	printf("-p(--port): sepcify server listen port.\n");
	printf("-h(--Help): print this help information.\n");
	return ;
}

int main(int argc, char **argv)
{
	 int sockfd = -1;
       	 int rv = -1;
	 struct sockaddr_in servaddr;
     	 struct sockaddr_in cliaddr;
	 socklen_t len;
	 int port = 0;
	 long int clifd;
	 int ch;
	 int on = 1;
	 pthread_t tid;

	 struct option opts[] = {
		 {"port", required_argument, NULL, 'p'},
	      	 {"help", no_argument, NULL, 'h'},
     		 {NULL, 0, NULL, 0}
	 };
	 while( (ch=getopt_long(argc, argv, "p:h", opts, NULL)) != -1 )	 
	 {
		 switch(ch)
		 {
			 case 'p':
				 port=atoi(optarg);
				 break;
			 case 'h':
				 print_usage(argv[0]);
				 return 0;
		 }
	 }
	 if( !port )	 
	 {
		 print_usage(argv[0]);
		 return 0;
	 }
	 sockfd=socket(AF_INET, SOCK_STREAM, 0);
	 if(sockfd < 0)	
       	 {
     		 printf("Create socket failure: %s\n", strerror(errno));
		 return -1;
	 }
	 printf("Create socket[%d] successfully!\n", sockfd);
	 setsockopt(sockfd, SOL_SOCKET, SO_REUSEADDR, &on, sizeof(on));
	 memset(&servaddr, 0, sizeof(servaddr));
	 servaddr.sin_family=AF_INET;
       	 servaddr.sin_port = htons(port);
	 servaddr.sin_addr.s_addr = htonl(INADDR_ANY);
	 rv=bind(sockfd, (struct sockaddr *)&servaddr, sizeof(servaddr));
	  if(rv < 0)	  
	  {
		  printf("Socket[%d] bind on port[%d] failure: %s\n", sockfd, port, strerror(errno));
		  return -2;
	  }
	  listen(sockfd, 13);
	  printf("Start to listen on port [%d]\n", port);
	  while(1)	   
	  {
		  printf("Start accept new client incoming...\n");
		  clifd=accept(sockfd, (struct sockaddr *)&cliaddr, &len);
		  if(clifd < 0)	     
		  {
			  printf("Accept new client failure: %s\n", strerror(errno));
			  continue;
		  }
		  printf("Accept new client[%s:%d] successfully\n", inet_ntoa(cliaddr.sin_addr), ntohs(cliaddr.sin_port));
			        /* !!!! Think about here: why pass clifd but not &clifd ? !!! */
		  thread_start(&tid, thread_worker, (void *)clifd);
	  }
	  close(sockfd);
	  return 0;
}
int thread_start(pthread_t * thread_id, THREAD_BODY * thread_workbody, void *thread_arg)
{
       	int rv = -1;
	pthread_attr_t thread_attr;
	if( pthread_attr_init(&thread_attr) )
	{
		printf("pthread_attr_init() failure: %s\n", strerror(errno));
		goto CleanUp;
	}
	if( pthread_attr_setstacksize(&thread_attr, 120*1024) )
	{
		printf("pthread_attr_setstacksize() failure: %s\n", strerror(errno));
		goto CleanUp;
	}
	if( pthread_attr_setdetachstate(&thread_attr, PTHREAD_CREATE_DETACHED) )
	{
		printf("pthread_attr_setdetachstate() failure: %s\n", strerror(errno));
		goto CleanUp;
	}

	/* Create the thread */

	if( pthread_create(thread_id, &thread_attr, thread_workbody, thread_arg) )
	{
		printf("Create thread failure: %s\n", strerror(errno));
		goto CleanUp;
	}
	rv = 0;
CleanUp:
	/* Destroy the attributes of thread */
	pthread_attr_destroy(&thread_attr);
	return rv;
}
void *thread_worker(void *ctx)
{
       	int clifd; int rv;
	char buf[1024];
	int i;
	if( !ctx )
	{
		printf("Invalid input arguments in %s()\n", __FUNCTION__);
		pthread_exit(NULL);
	}
	clifd = (long int)ctx;
	printf("Child thread start to commuicate with socket client...\n");
	while(1)
	{
		memset(buf, 0, sizeof(buf));
		rv=read(clifd, buf, sizeof(buf));
		if( rv < 0)
		{
			printf("Read data from client sockfd[%d] failure: %s and thread will exit\n", clifd,
					strerror(errno));
			close(clifd);
			pthread_exit(NULL);
		}
		else if( rv == 0)
		{
			printf("Socket[%d] get disconnected and thread will exit.\n", clifd);
			close(clifd);
			pthread_exit(NULL);
		}
		else if( rv > 0 )
		{
			printf("Read %d bytes data from Server: %s\n", rv, buf);
		}
		/* convert letter from lowercase to uppercase */
		for(i=0; i<rv; i++)
		{
			buf[i]=toupper(buf[i]);
		}
		rv=write(clifd, buf, rv);
		if(rv < 0)
		{
			printf("Write to client by sockfd[%d] failure: %s and thread will exit\n", clifd,strerror(errno));
			close(clifd);
			pthread_exit(NULL);
		}
	}
}
